The "unavailable" message typically means you have entered the pass-code incorrectly too many times. If your display is damaged then it is possible it thinks you did that. Get your phone repaired or buy a newer model (with an iPhone 7 I would seriously consider the latter).
For the iPhone Service Answer Center click here --> Choose Your Country or Region - Apple Support
Select your country.
For a cost estimate:
- Scroll down to "Get an estimate"
- Enter the service required
- Enter the iPhone model you have
- Enter the version of that model
- Click "Get estimate"
For instructions on how to get your iPhone, iPad, or iPod touch ready for service click here --> Prepare your iPhone or iPad for service - Apple Support
- "To protect your information and save time, follow these steps before you get service for your device."
Note that your data are essentially lost now. You can restore them on your repaired or new iPhone from a backup.
Read this support article to discover how to restore your iPhone, iPad, or iPod touch from a backup --> Restore your iPhone, iPad, or iPod touch from a backup - Apple Support